Conventionally, an information processing system configured of a plurality of data centers is provided. This type of information processing system is provided with a technique for selecting a data center that is the closest base as an access destination data center to be used by a user.
Moreover, a technique is known in the prior art in this type of information processing system for distributing loads by switching the access destination to another data center when the data center to be used by the user is under a heavy load. The above point is described with reference to FIG. 11. FIG. 11 illustrates an example of an information processing system. As illustrated in FIG. 11, an information processing system 1000 has a control center 1100, a data center DC-X, a data center DC-Y, a data center DC-Z, and a user terminal 1200. In the example illustrated in FIG. 11, the control center 1100 first detects that a heavy load has occurred in the data center DC-X that is currently used for “task A” by a user (S11). The control center 1100 then switches the access destination to the data center DC-Y which is the closest base to the user terminal 1200 among the other data centers DC-Y and DC-Z (S12).
Examples of the prior art include Japanese Laid-open Patent Publication No. 2000-137692, Japanese Laid-open Patent Publication No. 2005-4676, Japanese Laid-open Patent Publication No. 2011-76469, and Japanese Laid-open Patent Publication No. 2006-18710.
However, when switching the access destination to the closest data center, the data center that is the destination of the switching may have a heavy load. For example, a data center may be in a time zone in which the number of users using the data center is high. The system load on the data center that is the destination of the switching may become heavier during a time zone in which the number of users using the data center is high.